Abstract:
Fuel cell systems and related methods involving accumulators with multiple regions of differing water fill rates are provided. At least one accumulator region with a relatively more-rapid fill rate than another accumulator region is drained of water at shutdown under freezing conditions to allow at least that region to be free of water and ice. That region is then available to receive water from and supply water to, a fuel cell nominally upon start-up. The region having the relatively more-rapid fill rate may typically be of relatively lesser volume, and may be positioned either relatively below or relatively above the other region(s).